According to the instructions on Apple’s website, you go to settings tap on your Apple ID and that will open your iTunes Store account or you can manage your subscriptions. However when I tap on my Apple ID, nothing happens
On macOS, the http or https link on the webpage redirects with a itmss link, which should be configured to open in iTunes. It should be very similar on iOS (iTunes Store). If you use a different OS or browser, or have blocked/changed itmss links, then it won’t work with the link.
Alternatively, go there manually: iTunes on computer: menu Account﹥View my Account﹥Sign in﹥Purchase History﹥Settings﹥Subscriptions﹥Manage﹥
or on iOS: App Store: Account symbol or photo (upper right)﹥Your name/Apple ID﹥Subscriptions﹥
or on iOS: Settings﹥iTunes & App Store﹥Apple ID﹥View Apple ID﹥Subscriptions﹥
If you are signed in to the iTunes Store (with the correct Apple ID), then the link should take you right to the Manage Subscriptions page.
Indeed, that's what the instructions indicate, however, it appears to be text rather than a link as nothing happens when you tap on it. Since the only option at the bottom of the Apple ID screen is "Sign Out" that must mean it currently is signed in, so something is malfunctioning.
Nothing happens when I tap my Apple ID in settings
